http://ir.haramaya.edu.et//hru/handle/123456789/222 Mon, 19 Oct 2026 10:34:35 GMT 2026-10-19T10:34:35Z http://ir.haramaya.edu.et//hru/handle/123456789/8722 VARIABILITY AND CHANGE OF RAINFALL, TEMPERATURE, AND RAINFALL TELECONNECTION WITH PACIFIC OCEAN SEA SURFACE TEMPERATURE IN EASTERN HARARGHE Abdurezak Mohammed Yusuf; Berhanu Mengistu (PhD); Haftu Brhane Gebremichael (PhD) For thousands of years, the world's climate has been changing, and it is real, with serious consequences, notably in the water sector, which is essentially vulnerable. Climate variability is erratic, shifting unpredictably at the global, regional, and local levels. Knowledge of past climatic variability at local and regional scales can help build adaptation methods. As a result, a study was carried out and developed to examine changes, variability of rainfall, temperature, and its teleconnection with Pacific Ocean Sea surface temperature in Eastern Hararghe, Ethiopia using the CFSR dataset. The study is based on gridded CFSR rainfall and temperature data from 1983 to 2021 and 1983 to 2020 respectively. The spatial trend, variability, and distribution of rainfall and temperature were examined using ArcGIS 10.5 software. Mann-Kendall (MK) and Sen's slope estimator trend tests were also employed to analyze rainfall and temperature trends of change and anomaly. Correlation analysis was used to examine the relationship between seasonal rainfall with Pacific Ocean Sea surface temperature. The findings in the Eastern Hararghe zone show that the dry season (Bega) has higher seasonal fluctuation and the short rainy season (Belg) has higher variability. Rainfall trends declined significantly in most areas except the northernmost tip, but increased in Bega, particularly in the central region. NINO 3.4 SST had a decreasing effect on Kiremt season rainfall, while equatorial Pacific Ocean SST decreased rainfall. Droughts were generally connected with ENSO episodes in the study area. The study also found that the eastern half of the Eastern Hararghe experienced a significant increase in seasonal maximum temperatures, with the eastern section experiencing the largest increase. This raises concerns about potential drought and the need for increased attention to identify temperature extremes. The study also found that the typical seasonal maximum temperature has been higher than its minimum temperature over the last 38 years. Overall, the unpredictable rainfall, rising temperatures, and the biggest regional variance seen in the zone indicate that the area's agricultural sector is vulnerable and that all actors must work together to save agriculture output in Ethiopia's Eastern Hararghe Zone. To create an effective climate change adaptation strategy, it is vital to first analyze the current effects of climate on economic growth as well as extreme events. The study suggests further research on future climatic variability, temperature extremes, and human intervention in the Zone using various data sources, including CFSR grid data. 57p. Mon, 01 Apr 2024 00:00:00 GMT http://ir.haramaya.edu.et//hru/handle/123456789/8722 2024-04-01T00:00:00Z http://ir.haramaya.edu.et//hru/handle/123456789/5624 ELECTROWEAK THEORY OF NEUTRINO SCATTERING FROM SIGMA-HYPERON: CASE OF NEUTRAL CURRENT PROCESS Desu Belayneh Meshesha; Gashaw Bekele (PhD)_ In this thesis, we have carried out the theoretical formalism of the neutrino-induced neutral current(NC) neutral Sigma-hyperon elastic scattering process. The Feynman rules, Casimir’s Trick, Trace theorems and the form factor of weak neutral hadronic current have been constructed in terms of the relativistic expression of spin-average invariant amplitude. Moreover, by integrating over the Dirac-delta function has revealed the dependence of differential cross section on the incident energy and scattering angle. The kinematics of the process is set such that the incident and scattered particles are constrained on the zx-plane. The kinematics system in which neutrino-neutral sigma elastic scattering has been derived based on energy and momentum conservation laws. MatLab R2016a has been employed to generate the numerical results and plots of the unpolarized differential cross section for neutrino induced neutral-Sigma elastic scattering process in Lab frame at low and intermediate incident energy regions. For fixed values of incident energy, the peak of angular distribution increases with incident energy while at the same time getting sharper and shifting towards the forward scattering angle. Moreover, for fixed values of scattering angles, it is found out that the peak of energy distribution of the differential cross section is higher for lower scattering angles and occurs in the intermediate energy region. But at larger scattering angles, the peak drastically decreases and shifts toward the low energy region. Therefore, the elastic scattering under study within the framework of the SU(3) symmetry and Cabibbo vector-axial theory has been shown to be an intermediate energy process. 114 Sun, 01 May 2022 00:00:00 GMT http://ir.haramaya.edu.et//hru/handle/123456789/5624 2022-05-01T00:00:00Z